Rock compression in the lab (IMAGE) GFZ Helmholtz-Zentrum für Geoforschung Caption A rock sample is compressed in this apparatus. The sample is fitted with many sensors to detect acoustic emissions, i.e. micro-earthquakes. Credit GFZ German Research Centre for Geosciences Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.